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Shadow Theory

Section 5 9 October 2026

Physical relative scores without a density cap

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5 Physical relative scores without a density cap

Let ξ=(ξ0,…,ξd−1)\xi=(\xi_0,\ldots,\xi_{d-1}) be all standardized physical entrance coordinates and let Γd(ξ)=∏iϕ(ξi)\pGam_d(\xi)=\prod_i\phi(\xi_i). Conditional on the same retained X=xX=x, write the actual density as

px(ξ)=Γd(ξ)fx(ξ),∂ifx=fxsi,xdistributionally,Ji=∫∣si,x∣2px dξ dμX(x)<∞. p_x(\xi)=\pGam_d(\xi)f_x(\xi),\qquad \partial_i f_x=f_xs_{i,x}\quad\hbox{distributionally},\qquad J_i=\int |s_{i,x}|^2p_x\,d\xi\,d\mu_X(x)<\infty. (5.1)

The score is assigned arbitrarily on zero-density sets. In particular ∑iJi\sum_iJ_i concerns the full conditional density, including every archive and unused future source. The comparison Gaussian fixes the analysis coordinates and describes the quantum stock; it does not specify the actual law pxp_x.

Lemma 5.1 (Moments and boundary traces from weak scores)

Under (5.1), the actual second moment Mi=Eξi2M_i=\mathbb E\xi_i^2 is finite and the ordinary physical Fisher information satisfies

Iiabs=Ji+2−Mi≥0,Mi≤Ji+2. I_i^{\rm abs}=J_i+2-M_i\geq0, \qquad M_i\leq J_i+2. (5.2)

Restrict the complete actual density to the physical box ∣ξi∣≤Ri|\xi_i|\leq R_i and extend by zero in the quantile coordinates ui=Φ(ξi)u_i=\Phi(\xi_i). Its directional variations obey

Vi≤DRi{Ji+Ji+2},DR=2πeR2/2. V_i\leq D_{R_i}\{\sqrt{J_i}+\sqrt{J_i+2}\}, \qquad D_R=\sqrt{2\pi}e^{R^2/2}. (5.3)

For a common radius RR, total score J=∑iJiJ=\sum_iJ_i, one writer and nn active archives,

Sn≤DRn+4{J+J+2d}. S_n\leq D_R\sqrt{n+4}\{\sqrt J+\sqrt{J+2d}\}. (5.4)
Proof

First prove finiteness rather than assuming the integration by parts is legitimate. Choose even compact smooth cutoffs 0≤χR≤10\leq\chi_R\leq1, nonincreasing in ∣ξi∣|\xi_i|, increasing to one, with uniformly bounded ξiχR′\xi_i\chi_R'. Set MR=E(ξi2χR)M_R=\mathbb E(\xi_i^2\chi_R). Integration by parts against the compact test ξiχR\xi_i\chi_R gives

MR=E(χR+ξiχR′)+E(ξiχRsi)≤1+MRJi. M_R=\mathbb E(\chi_R+\xi_i\chi_R')+ \mathbb E(\xi_i\chi_Rs_i) \leq1+\sqrt{M_RJ_i}.

Spectator cutoffs can be exhausted: the active test is bounded and its score term is integrable by Cauchy. Solving the quadratic gives MR≤[(Ji+Ji+4)/2]2M_R\leq[(\sqrt{J_i}+\sqrt{J_i+4})/2]^2; monotone convergence proves Mi<∞M_i<\infty. Now ξisi\xi_i s_i is integrable. Removing the cutoff, its bounded derivative term tends to zero by dominated convergence, giving Eξisi=Mi−1\mathbb E\xi_i s_i=M_i-1. The ordinary score is si−ξis_i-\xi_i, so

Iiabs=E(si−ξi)2=Ji+2−Mi. I_i^{\rm abs}=\mathbb E(s_i-\xi_i)^2=J_i+2-M_i.

This proves (5.2) without presupposing the moment.

For almost every xx, the one-coordinate marginal pi,xp_{i,x} has weak derivative equal to the integrated joint derivative. Conditional expectation and Cauchy imply ∥pi,x′∥1≤Ii,xabs\|p_{i,x}'\|_1\leq\sqrt{I_{i,x}^{\rm abs}}. An integrable nonnegative W1,1(R)W^{1,1}(\mathbb R) density tends to zero at both infinities, so 2sup⁡pi,x≤∥pi,x′∥12\sup p_{i,x}\leq\|p_{i,x}'\|_1. On the box interior, differentiating in uiu_i introduces 1/ϕ(ξi)≤DRi1/\phi(\xi_i)\leq D_{R_i}; score Cauchy bounds the integrated interior variation by DRiJiD_{R_i}\sqrt{J_i}. At each of the two quantile faces the zero extension contributes the trace of the density. Integrating all other coordinates bounds their sum by

DRi∫[pi,x(Ri)+pi,x(−Ri)] dμX(x)≤DRiJi+2. D_{R_i}\int[p_{i,x}(R_i)+p_{i,x}(-R_i)]\,d\mu_X(x) \leq D_{R_i}\sqrt{J_i+2}.

BV traces or a limiting regular face justify the same assertion for weak densities. This proves (5.3). Finally apply weighted Cauchy to the coefficients (2,1,…,1)(2,1,\ldots,1) in SnS_n. Their squared sum is n+4n+4; including unused coordinates in JJ and dd only enlarges the upper bound. This proves (5.4).

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Higher moments, when assumed, give a useful separate tail estimate:

τ≤∑iE∣ξi∣pRip. \tau\leq\sum_i\frac{\mathbb E|\xi_i|^p}{R_i^p}. (5.5)

The second-moment part of this estimate follows from the weak-score hypothesis. A twentieth moment does not follow from that argument and will be explicitly required for the next row.

Corollary 5.2 (A finite cap-free preparation row)

Include one writer, 100100 warmup archives, and one untouched subsequent measurement source, so d=102d=102. Suppose the actual complete conditional law satisfies

∑iJi≤100,∑iE∣ξi∣20≤1015. \sum_iJ_i\leq100,\qquad \sum_i\mathbb E|\xi_i|^{20}\leq10^{15}.

Use D=A=50D=A=50, the complete entrance box ∣ξi∣≤10|\xi_i|\leq10, and analysis grid N=1040N=10^{40}. Then the preparation and all later current-zero holds satisfy

E100≤2.00006×10−16,Δbox:=Vw4 2100+2E100<5.192874163845×10−8,TV⁡(Law⁡(R100,Z100),U⊗Law⁡(Z100))<1.005192874164×10−5,Pr⁡(some wrong warmup copy)<1.000000002000061×10−5.\begin{align}E_{100}&\leq2.00006\times10^{-16},\tag{5.6}\\ \Delta_{\rm box}:=\frac{V_w}{4\,2^{100}}+2E_{100} &<5.192874163845\times10^{-8},\tag{5.7}\\ \pTV(\pLaw(R_{100},Z_{100}),\pUnif\otimes\pLaw(Z_{100})) &<1.005192874164\times10^{-5},\tag{5.8}\\ \Pr(\hbox{some wrong warmup copy}) &<1.000000002000061\times10^{-5}. \tag{5.9}\end{align}

The untouched measurement source is part of Z100Z_{100}, not averaged out.

Proof

The elementary exponential enclosure gives D10<1.31×1022D_{10}<1.31\times10^{22}. Using 102<10.1\sqrt{102}<10.1, 104<10.2\sqrt{104}<10.2 and 304<17.44\sqrt{304}<17.44 in Lemma 5.1 gives

Vw<2.6331×1023,S100<3.6665328×1024<3.67×1024,H100∗<2×1024. V_w<2.6331\times10^{23},\quad S_{100}<3.6665328\times10^{24}<3.67\times10^{24},\quad H_{100}^*<2\times10^{24}.

The last inequality retains the positive mass term 100100 in H100∗H_{100}^*. Choose c=3c=3, η=10−110\eta=10^{-110}, k=24k=24. Gaussian upper tails and exponential bounds give

γ=e−300<10−130,Φ(−24)<η/2,ρA=e−2600<10−1100,tA=Φ(−76)<10−1200,aD=Φ(−53)<10−600.\begin{aligned}\gamma=e^{-300}&<10^{-130},& \Phi(-24)&<\eta/2,\\ \rho_A=e^{-2600}&<10^{-1100},& t_A=\Phi(-76)&<10^{-1200},\\ a_D=\Phi(-53)&<10^{-600}.&& \end{aligned}

Thus δ<2×10−130\delta<2\times10^{-130} and β<3×10−110\beta<3\times10^{-110}. In particular β+4Nδ<3×10−45\sqrt{\beta+4N\delta}<3\times10^{-45} and β<2×10−55\sqrt\beta<2\times10^{-55}. Therefore

E100≤4×10242×1040+(2×1024)(3×10−45)=2.00006×10−16. E_{100}\leq\frac{4\times10^{24}}{2\times10^{40}} +(2\times10^{24})(3\times10^{-45}) =2.00006\times10^{-16}.

The ideal boxed writer fee is bounded by 2.6331×1023/(4 2100)2.6331\times10^{23}/(4\,2^{100}) <5.192874123844×10−8<5.192874123844\times10^{-8}. The actual complete-box tail is at most 1015/1020=10−510^{15}/10^{20}=10^{-5}. Substitution in Theorem 4.2 gives the stated rational decimal ceilings; the copy ceiling includes the additional 4×10−314\times10^{-31} bad-set term.

For reproducible directed inequalities one may use 2π<2.51\sqrt{2\pi}<2.51 and bound e50e^{50} by its positive Taylor sum through degree 200200 plus the next term divided by 1−50/2021-50/202. For the lower exponential bounds used in the tails, e>∑j=051/j!=163/60e>\sum_{j=0}^5 1/j!=163/60 suffices, together with Φ(−x)≤e−x2/2/(2x)\Phi(-x)\leq e^{-x^2/2}/(2x) for x>0x>0. All row decisions consequently reduce to rational inequalities.

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An explicit non-Born member of this class consists of 102102 independent actual centered Gaussians of variance 5/25/2 in the standardized physical coordinates. Its full relative Fisher is

J=102(1−2/5)2(5/2)=91.8, J=102(1-2/5)^2(5/2)=91.8,

and its twentieth-moment sum is

102 (19!!) (5/2)10=6.368862690925598…×1014<1015. 102\,(19!!)\,(5/2)^{10}=6.368862690925598\ldots\times10^{14}<10^{15}.

Its ground-relative density is unbounded. Its quantile Fisher is infinite: for one coordinate the integrand contains x2p(x)/ϕ(x)2x^2p(x)/\phi(x)^2, whose exponential factor grows at infinity. Independence is used only to exhibit this member; neither the theorem nor its constants impose it.

5.1 Finite-resource existence and growing conditional prefixes

Theorem 5.3 (Uniform writer-score family and all retained records)

Let a consistent stock family provide, for every finite nn, the full conditional density of the writer, nn warmup sources, one unused future source, and retained XX. Suppose its weak relative scores satisfy

Jw(n)≤J∗<∞for every n,Ji(n)<∞for every other coordinate of each prefix. J_w(n)\leq J_*<\infty\quad\hbox{for every }n, \qquad J_i(n)<\infty\quad\hbox{for every other coordinate of each prefix}.

Then for every 0<ε<10<\varepsilon<1 there are finite nn, finite physical cutoffs and finite separations D,AD,A for which complete retained-archive freshness is at most 3ε/43\varepsilon/4 and the probability of any wrong warmup copy-and-hold record is less than 0.42ε0.42\varepsilon.

Proof

Choose Rw2≥8(J∗+2)/εR_w^2\geq8(J_*+2)/\varepsilon. The writer tail is at most ε/8\varepsilon/8 and

Vw≤V∗:=DRw(J∗+J∗+2), V_w\leq V_*:=D_{R_w}(\sqrt{J_*}+\sqrt{J_*+2}),

independently of nn. Choose finite n≥1n\geq1 so that V∗/(4 2n)≤ε/4V_*/(4\,2^n)\leq\varepsilon/4. For this chosen full prefix, choose each of the n+1n+1 source cutoffs to satisfy Ri2≥8(n+1)(Ji(n)+2)/εR_i^2\geq8(n+1)(J_i(n)+2)/\varepsilon. Their aggregate tail is at most ε/8\varepsilon/8; hence τ≤ε/4\tau\leq\varepsilon/4. All boxed source variations are finite by Lemma 5.1. Set S=SnS=S_n and H=n+S/2H=n+S/2 and choose

N≥max⁡{1,8nS/ε},β≤ε2512n2H2,δ≤ε22048n2NH2. N\geq\max\{1,8nS/\varepsilon\},\qquad \beta\leq\frac{\varepsilon^2}{512n^2H^2},\qquad \delta\leq\frac{\varepsilon^2}{2048n^2NH^2}. (5.10)

The two terms in EnE_n are at most ε/(16n)\varepsilon/(16n) each, so En≤ε/(8n)E_n\leq\varepsilon/(8n). Thus freshness is at most ε/4+ε/4+ε/(4n)≤3ε/4\varepsilon/4+\varepsilon/4+\varepsilon/(4n)\leq3\varepsilon/4, and the all-record bound is at most

ε(14+1512 n+18)≤ε(38+489)=299712ε<0.42ε. \varepsilon\left(\frac14+\frac{1}{\sqrt{512}\,n}+\frac18\right) \leq\varepsilon\left(\frac38+\frac4{89}\right) =\frac{299}{712}\varepsilon<0.42\varepsilon.

Here 512>89/4\sqrt{512}>89/4. The factor nn in (5.10) prices all own-event records; a schedule controlling freshness alone does not automatically do so.

It remains to realize these positive β,δ\beta,\delta thresholds with finite Gaussian parameters. Fix c=3c=3 and choose η\eta sufficiently small for the source-end part of β\beta. Choose finite kk with Φ(−k)<η/2\Phi(-k)<\eta/2. Increase DD until e−2Dce^{-2Dc} is below both the desired displacement allocation and η/2\eta/2, and until Φ(−(D−c))\Phi(-(D-c)) and Φ(−(D+c))\Phi(-(D+c)) meet their respective allocations. Increase A>kA>k until e−2A(A−k)e^{-2A(A-k)} and Φ(−(2A−k))\Phi(-(2A-k)) meet the remaining allocations. Lemma 3.3 proves the required map and copy bounds. All choices are finite after this finite prefix has been selected. The translations and conjugated holding swaps described above implement the corresponding smooth prescribed parent.

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The order of these choices matters. A common second-moment box whose total moment grows like b(n+1)b(n+1) would require R2≥b(n+1)/τR^2\geq b(n+1)/\tau. Its writer variation enclosure contains eb(n+1)/(2τ)e^{b(n+1)/(2\tau)}, which can grow faster than 2n2^n. The theorem fixes the writer cutoff before increasing the source count, assigning costly source variations to the later grid and separation choices.

Proposition 5.4 (Why finite-prefix smoothness is insufficient)

There is a consistent actual stock family for which every finite physical prefix has a smooth positive density, finite relative Fisher and bounded coordinate second moments, but the complete ideal baker output satisfies, for every n≥1n\geq1,

TV⁡(Law⁡(Rn,Zn),U⊗Law⁡(Zn))>518912550>0.4. \pTV(\pLaw(R_n,Z_n),\pUnif\otimes\pLaw(Z_n))> \frac{5189}{12550}>0.4.
Proof

Take independent standard normals Y,G1,G2,…Y,G_1,G_2,\ldots and set Zjin=Y+2−6jGjZ_j^{\rm in}=Y+2^{-6j}G_j; use writer u=Φ(Y)u=\Phi(Y) and sources vj=Φ(Zjin)v_j=\Phi(Z_j^{\rm in}). Every finite covariance is nonsingular. For a prefix containing the writer and mm sources, differentiation at fixed source coordinates gives

∂Ylog⁡(p/Γ)=∑j=1m212j(Zjin−Y),Jw(m)=∑j=1m212j. \partial_Y\log(p/\pGam)=\sum_{j=1}^m2^{12j}(Z_j^{\rm in}-Y), \qquad J_w^{(m)}=\sum_{j=1}^m2^{12j}.

A bank with nn warmup archives and an untouched receiver has m=n+1m=n+1. Thus this family fails the uniform full conditional writer hypothesis, although its writer marginal is exactly standard normal. The final archive bnb_n reveals vn=2bn−⌊2bn⌋v_n=2b_n-\lfloor2b_n\rfloor, hence ZninZ_n^{\rm in}. Define the archive prediction r^={2nΦ(Znin)}\widehat r=\{2^n\Phi(Z_n^{\rm in})\}. Circle distance obeys

dist⁡T(r,r^)≤2−5n∣Gn∣/2π. \operatorname{dist}_{\mathbb T}(r,\widehat r) \leq 2^{-5n}|G_n|/\sqrt{2\pi}.

Since 2π>2.5\sqrt{2\pi}>2.5, the event ∣Gn∣≤0.8|G_n|\leq0.8 implies this distance is at most 0.010.01 for all n≥1n\geq1. Under an independent uniform remainder, the same archive-dependent circle interval has probability 0.020.02. Meanwhile

Pr⁡(∣Gn∣≤0.8)>1.6(1−0.32)2.51. \Pr(|G_n|\leq0.8) >\frac{1.6(1-0.32)}{2.51}.

Subtracting 0.020.02 gives 5189/125505189/12550. The strict inequality follows from e−0.32>1−0.32e^{-0.32}>1-0.32 and 2π<2.51\sqrt{2\pi}<2.51.

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5.2 Two distinct cap-free limits

Proposition 5.5 (Fixed-law finite-map convergence)

Fix nn and any complete entrance law with conditional L1L^1 densities fxf_x. As D,A→∞D,A\to\infty,

TV⁡((Tn)#μ,(Bn)#μ)⟶0. \pTV((\mathcal T_n)_\#\mu,(\mathcal B_n)_\#\mu)\longrightarrow0.

No cap or Fisher condition is needed for this fixed-law assertion.

Proof

For fixed u<1/2u<1/2 and v∈(0,1)v\in(0,1), FD−1(u)=−D+Φ−1(2u)+o(1)F_D^{-1}(u)=-D+\Phi^{-1}(2u)+o(1) and its minority posterior tends to zero. The copy position is −A+Φ−1(v)+o(1)-A+\Phi^{-1}(v)+o(1), and the return and archive outputs tend to (2u,v/2)(2u,v/2). Reflection gives the other branch. Consequently B−1TD,A→IB^{-1}T_{D,A}\to I almost everywhere. Finite iteration excludes only the finite family of dyadic cuts and their preimages. The corresponding full difference maps preserve Lebesgue measure. For bounded continuous hh on the closed cube, dominated convergence gives ∥h∘K−h∥1→0\|h\circ K-h\|_1\to0. Approximate an arbitrary f∈L1f\in L^1 by such hh and use

∥f∘K−f∥1≤2∥f−h∥1+∥h∘K−h∥1. \|f\circ K-f\|_1\leq2\|f-h\|_1+\|h\circ K-h\|_1.

This proves TV convergence on each XX fibre. Dominated convergence in the actual XX law completes the argument.

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A qualitative growing-family sufficient condition is stronger: require that UU conditional on the entire consistent source tape and XX has an L1L^1 density. Dyadic cell averaging converges in L1L^1 on each such fibre. Its error is precisely the ideal complete-remainder freshness error before projecting to a finite retained tape. Dominated convergence allows a finite nn to be selected for each tolerance; Proposition 5.5 then selects finite separations for that fixed prefix. Proposition 5.4 explains why absolute continuity of every finite prefix is weaker than this premise.

Proposition 5.6 (A finite-resource obstruction without a density cap)

For n=44n=44 and D=A=12D=A=12, there is a smooth actual complete law with physical relative Fisher exactly 100100 whose final marginal ready distance from uniform exceeds 0.940.94.

Proof

Take actual writer Q0∼N(10,1)Q_0\sim N(10,1) and independent standard-normal actual archives. The entrance ratio is e10Q0−50e^{10Q_0-50}, with physical relative score 1010 in the writer direction and zero in every archive direction. Its relative density is unbounded. The Gaussian upper-tail inequality implies Φ(−8.1)<0.005/244\Phi(-8.1)<0.005/2^{44} and Pr⁡(Q0>8.1)>0.96\Pr(Q_0>8.1)>0.96. On this event every ideal digit is right and every ideal remainder is greater than 0.9950.995. For each actual archive, exclude its initial quantiles outside [10−12,1−10−12][10^{-12},1-10^{-12}]; the aggregate exclusion probability is at most 88×10−1288\times10^{-12}. With c=3,k=8c=3,k=8, Lemma 3.3 gives, on the right good branch, a ready-coordinate error per cycle at most 10−48+10−4110^{-48}+10^{-41}. Induction bounds the accumulated error by (244−1)(10−48+10−41)<10−20(2^{44}-1)(10^{-48}+10^{-41})<10^{-20}. Every actual remainder therefore stays in the right good branch and the final one exceeds 0.990.99. Thus

Pr⁡(R44>0.99)>0.96−88×10−12, \Pr(R_{44}>0.99)>0.96-88\times10^{-12},

whereas uniform assigns 0.010.01 to this event. The difference exceeds 0.940.94. Complete archive-conditioned distance is at least this marginal distance by projection. This is a finite-resource counterexample, not a failure of an upper estimate.

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For comparison, the cap-based physical-score row does survive with C=10C=10, J≤100J\leq100, R=6R=6, n=44n=44, D=A=12D=A=12 and N=1019N=10^{19}. The direct cap trace bound is Vi≤DRJi+2CV_i\leq D_R\sqrt{J_i}+2C, and the complete-box tail is 2CdΦ(−R)2Cd\Phi(-R). With d=46d=46, including the untouched future source, D6<1.65×108D_6<1.65\times10^8 and Φ(−6)<10−9\Phi(-6)<10^{-9} give S44<1.2×1010S_{44}<1.2\times10^{10} and Vw<1.65000002×109V_w<1.65000002\times10^9. Using δ<2×10−30\delta<2\times10^{-30}, β≤2×10−12+10−18\beta\leq2\times10^{-12}+10^{-18} in (4.8) gives E44cap≤1.864000022×10−8E_{44}^{\rm cap}\leq1.864000022\times10^{-8} and freshness <2.440519056475×10−5<2.440519056475\times10^{-5}. Alternatively, the complete quantile-score row n=18,C=10,Jq≤104n=18,C=10,J^{\rm q}\leq10^4 with N=1015N=10^{15} gives E18cap≤1.8097009×10−10E_{18}^{\rm cap}\leq1.8097009\times10^{-10} and freshness ≤9.5367793580805×10−5\leq9.5367793580805\times10^{-5}. These are different admitted-law classes; the cap-free row of Corollary 5.2 changes both the class and the resources.